April 2013 Gardening To-Do List: Zone 5

Zone 5’s average last frost date is April 15 but don’t count on it. After the first day of Spring, many of us are chomping at the bit to get out in the garden and begin spring planting. A little caution is called for since the weather can be unpredictable and a late freeze or snowstorm can undo a lot of hard work. Prepare to protect seedlings in the garden from frost by preparing cages and stakes that you can cover with cloth on cold nights. Click on the map at right to find your zone.

Perennials

Clean your perennial beds by hand to avoid damaging emerging shoots. Then apply a balanced, organic fertilizer over the old mulch and top dress with fresh mulch.

Apply a trowel-full of wood ashes and one of manure or compost to your peonies – more if you have large plants. If your peony never blooms, it is either planted too deep or in a too-shady location.

If the ground has thawed, divide and replant perennials such as asters, bee balm, and hostas.

Remove and destroy old leaves of your irises and remove any surrounding debris in which the eggs of the dreaded iris borer may have spent the winter.

Fertilize spring blooming bulbs in March or early April. Plant summer and fall flowering bulbs as soon as the soil has warmed.

Annuals

Plant cool season annuals like pansies as soon as the ground has thawed and dried, usually by the end of March or first of April.

Usually by the beginning of April, you can plant hardy annuals such as geraniums and even petunias. A light frost usually does them no harm but a hard freeze will.

Vegetables

To enjoy abundant harvests before hot weather arrives, plant peas, lettuce, and spinach early this month.

Use row covers to protect seedbeds from birds and late frosts. Once the seedlings are a couple of inches tall, it is usually safe to remove the covers. Don’t leave the covers too long since pollinators need to have access to the flowers.

Set out hardened-off seedlings of cabbage and broccoli a couple of weeks before the last frost date. When you plant the young seedlings in the ground, set them deeper than they were growing in the pot, so the soil level is just below the first set of leaves.

Start cucumber, cantaloupe, summer squash, and watermelon seeds indoors in peat pots since vegetables that vine do not transplant well when the roots are disturbed. Don’t put these seedlings or those of tomatoes, peppers or basil outdoors until ALL danger of frost is past, then wait another day or two.

Locate plants in a new section of the garden on a three-year rotation to help prevent disease problems.

Trees/Shrubs

Apply dormant oil to shrubs and fruit trees early in the month to kill most insect eggs. Make sure you do this while plants are dormant and air temperatures will be above freezing for at least 24 hours.

Plant bare root trees when the soil is thawed and dried, usually in early April.

If you haven’t done so yet, pound in evergreen fertilizer stakes or apply a slow release granular fertilizer to your evergreens.

Early in April, before growth begins, prune dead, broken and wayward branches from hybrid tea, grandiflora and floribunda roses. You know it is time to prune roses when the forsythia blooms, just ahead of dandelions blooming and lilac leaves appearing. Apply a slow release granular fertilizer.

Treat blue hydrangeas with aluminum sulphate to keep them blue. Put down lime to turn them pink.

If you wrapped the trunks of young trees to guard against sun-scald and frost cracking over the winter, now is the time to remove that protection. If left in place, the coverings can trap heat, causing injury to the bark.

Lawn/Turf

One hour spent pulling weeds now will save you many hours later on. Use a forked tool to dig up weeds with long taproots. To kill the annoying weeds that sprout in gravel, brick, and stone paths, spray them with plain white vinegar. A great way to deal with dandelions, as long as they have never been treated with chemicals, is to eat them before they bloom!

After your first mowing, apply fertilizer. Add pre-emergent weed killer for crabgrass if necessary. Crabgrass seed generally germinates after the soil temperature has reached 50 degrees, and it requires about 5 consecutive days of 50 degree soil temperature. When you see the first dandelion bloom, it is time to apply crabgrass control.

Garden photo: Wikimedia Commons/Southernfoodwaysalliance

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